1. Field of the Invention
This invention pertains to the art of material handling vehicles and more specifically to a tractor loader having lift arms carrying a bucket or other tool. An attachment mounting frame pivots on the lift arms and is adapted to couple with various attachments.
2. Description of the Prior Art
A tractor loader vehicle of the type to which the present invention pertains is disclosed in U.S. Pat. No. 3,372,996; inventor, James J. Bauer; issued 15 May 1973 and assigned to the assignee of the present invention. Such a vehicle will often be referred to as an end loader when equipped with a bucket or other material handling shovel. The lift arms, however, have a pivoted mounting frame at their forward ends which is capable of mounting various attachments other than a bucket thus converting the vehicle to other uses. A prime example is a backhoe.
In the method employed according to this patent, the backhoe will have a carrier which is engaged by the pivoted mounting frame on the end of the lift arms. A pair of lift cylinders for raising and lowering the arms are actuated to lower the mounting frame behind the carrier. Tilt cylinders on the lift arms pivot the mounting frame providing a second degree of motion to the frame. By manipulating the lift and tilt cylinders, the backhoe can be lifted and tilted while being transferred to a working position on the front of the machine. A mounting frame of the type referred to is disclosed in U.S. Pat. No. 3,672,521, Bauer et al, issued June 27, 1972 which is also assigned to the assignee of the present invention.